1. Field
The present invention relates to devices which are used to dam or block the drain, vent, waste plumbing systems above the test tee, such that the system can be filled with air or water to hydraulically test the system.
2. State of the Art
When a plumber installs a drain, vent, waste system in either new construction or in remodeling, a test tee is installed in the low point of the drain, vent, waste system. When the drain, vent, waste system is completed, it must be tested hydraulically to insure the absence of leaks in the system. To accomplish the hydraulic test, the plumbing system must be blocked or dammed at the test tee so that the system can be filled with water above the test tee.
Heretofore, it has been common practice to utilize an inflatable rubber or elastomeric device which can be installed through the lateral opening in the tee to block the plumbing system above the tee. Once installed above the lateral opening in the test tee, the block-off device is inflated so as to make a fluid tight seal with the plumbing system at the test tee. Water is then introduced into the plumbing system and allowed to stand in the plumbing system above the test tee to determine if there are any leaks in the system.
Following the test, the inflatable device must be removed to allow the water to drain from the system. The system normally contains a substantial volume of water under a substantial head or pressure. In deflating the damming device, care must be taken to prevent the device from being swept into the drain conduit downstream from the test tee. Otherwise, the device is likely to be caught in the drainage conduit and must then be removed to alleviate the chance of having the damming device being swept deep into the drain conduit, a tether is commonly attached to the device. If the device is swept into the drainage conduit, the tether holds the device close to the test tee and after the water has drained from the plumbing system being tested, the tether is used to withdraw the damming device from the drainage conduit through the test tee.
Unfortunately, it has been the sad experience of many plumbers to have the tether break as the damming device is being swept into the drainage conduit by the head pressure of the water in the system being tested. Alternatively, and just as perplexing, the tether can become entangled with the damming device in the drainage conduit such that even though the tether extends out of the test tee, the damming device cannot be extracted from the drainage conduit.
In my previous U.S. Pat. No. 4,763,510 issued on Aug. 16, 1988, I disclosed a one-piece, molded sealing element that was cup-shaped and fit within a test tee. When installed in a test tee, the cup-shaped element formed a dam so that the drain, vent, waste system could be filled with water to hydraulically test the system. Following the hydraulic test, the sealing element was broken and removed from the test tee in a two step procedure. In the first step, the circular disc portion of the cup-shaped element was broken from the cylindrical sidewall of the cup-shaped element. In the second step, the remaining cylindrical sidewall portion was pried loose from the barrel of the plastic tee and then removed from the side entry of the plastic tee.
It has been found that it would be highly desirable to provide an inexpensive, improved device for blocking or damming the plumbing system at a test tee, with the improved device being adapted to be ripped or torn out of the barrel of the test tee in a simplified procedure in which the device is removed in its entirety from the test tee by ripping the central, portion of the circular disc in a spiral ripping motion that extends to the perimeter portion of the device to rip or pull the entire device from the test tee.